89 votes

Why didn't C++ specify filename extensions?

Because it's not important to ... anything. The compilers don't care. The editors don't care. Back in the day, some operating systems didn't even HAVE "file extensions". DOS mandated them, ...
Will Hartung's user avatar
  • 12.3k
77 votes
Accepted

Why did base64 win against uuencode?

I’m not sure about specific events, but I think the main reason Base64 “won” is that it’s one of the binary encodings supported by MIME, and MIME took over. So perhaps the question then becomes two-...
Stephen Kitt's user avatar
57 votes
Accepted

Did INI files work in a different way on Windows 3.x than today?

You have been wrong for 30 years. I wrote the test program below and compiled it with Borland Pascal 7: uses WinTypes, WinProcs, WinCrt; var buffer: string; len: Integer; begin len := ...
user3840170's user avatar
  • 23.1k
48 votes

How can I tell whether a DOS-looking exe. requires a 32-bit CPU to run?

Plain DOS executables, in either COM or MZ format, don’t provide this information in their headers (when there is one — COM format doesn’t have a header). The only reliable way to determine whether a ...
Stephen Kitt's user avatar
45 votes

Do the holes in Jacquard loom punched cards represent input data or program code?

Do the holes in Jacquard loom punched cards represent input data or program code? yes. Let me tell you a story. Somebody I used to work with many years ago was flying into the USA (or it might have ...
JeremyP's user avatar
  • 11.8k
39 votes
Accepted

Magnetic exposure to floppy disk damages file system and requires complete reformat?

A formatted disk contains markers which identify the start of each track and the start of each sector within the track. These markers are fixed magnetic sequences that are picked up by the drive ...
Chenmunka's user avatar
  • 8,141
37 votes

Why did base64 win against uuencode?

The problem with uuencode is that the format was not robust in the face of some of the really crufty mail software and gateways into and out of proprietary non-SMTP and non-ASCII mail systems of the ...
pndc's user avatar
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36 votes
Accepted

Why didn't C++ specify filename extensions?

The first edition of Stroustrup's "The C++ Programming Language" (1986) consistently uses a ".h" extension for C++ header files and ".c" for C++ source files. C and C++ ...
Keith Thompson's user avatar
34 votes
Accepted

How did large .COM files work?

Most large files (over 64KiB) with a .COM extension are really MZ executables; the DOS loader doesn’t care whether the extension is .EXE or .COM, it uses the MZ signature to identify the format. This ...
Stephen Kitt's user avatar
33 votes

Document format for a DOS word processor where control commands begin with a dot

Almost definitely WordStar or a compatible program such as NewWord. dot commands at the top. From the WordStar 3.3 manual: .op - omit page numbers .mt1 - margin top 1 line .hm1 - heading margin 1 ...
manassehkatz-Moving 2 Codidact's user avatar
30 votes

Magnetic exposure to floppy disk damages file system and requires complete reformat?

The main thing is that there is no such thing as a "quick format" - That term is entirely misleading terminology invented by Microsoft. Quick Format doesn't "format" anything. What MS calls a "Quick ...
tofro's user avatar
  • 35k
30 votes
Accepted

What were the differences in floppy disk formats between Amiga and IBM/PC compatible computers?

The Amiga disk format stores 512 bytes per sector, 11 sectors per track (a track is one side of a cylinder), double sided (i. e. 2 tracks per cylinder) with 80 cylinders per disk, which makes 80 * 2 * ...
blubberdiblub's user avatar
30 votes
Accepted

Why does the default base64 encoding use forward slash /?

I'm not aware of a (published) rationale for the choice of '+' and '/' as encoding characters, as well as '=' for padding / end-of-message, and I strongly suspect there isn't one. Base64 was designed ...
Michael Graf's user avatar
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28 votes

How well known and how commonly used was Huffman coding in 1979?

According to Google Scholar, Huffman’s 1952 paper had 326 citations by 1979, which given the volume of publication at the time means it was well-known, as far as can be determined now. Most ...
Stephen Kitt's user avatar
27 votes
Accepted

What format is the (Timex) Sinclair ZX Spectrum SCREEN$/.SCR file

For a standard screen, compatible with ZX Spectrum, a SCREEN$ file is 6912 bytes. It's just a dump of the screen memory. The first 6144 bytes store the screen bitmap: 256x192 pixels, 1 bit per pixel (...
mcleod_ideafix's user avatar
25 votes
Accepted

How well known and how commonly used was Huffman coding in 1979?

Well, in fact, a closely related question has been asked (and answered) few years ago: What is the history of data compression tools on personal computers? From that question, and its answer, it ...
introspec's user avatar
  • 4,172
24 votes

What was the purpose of the ‘overlay number’ field in the MZ executable format?

TL;DR: The Number is Used to Manage Multiple Overlays in a single EXE File. Microsofts linker (LINK) can create single EXE files containing multiple overlays (up to 63) which are simply numbered in ...
Raffzahn's user avatar
  • 223k
23 votes

Where and when did the ".s" suffix for assembly-language source files originate?

I asked Ken Thompson. The s stands for source, because it was the only source at the time.
Russ Cox's user avatar
  • 331
22 votes
Accepted

What was the end of line convention for text files on the 8-bit Commodores

C64 Basic used a CR as EOL for disk files. (source: Commodore SX-64 User's Guide, page 22: “CR stands for the CHR$ code 13, the carriage return, which is automatically PRINTed at the end of ever ...
scruss's user avatar
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22 votes
Accepted

What were the most common software distribution formats for MacOS Classic?

Up until things like Compuserve and AOL (and then Internet for the masses) came around, floppy disks would have more or less been the only option. (CD-ROM drives in consumer machines arrived only a ...
ssokolow's user avatar
  • 6,765
20 votes
Accepted

What determines which architecture an a.out executable runs on?

The a_midmag field contains a machine identifier, which can be used on platforms which support that field. a_midmag is a 32-bit value stored in host byte-order (fun already), and bits 16 to 23 give ...
Stephen Kitt's user avatar
20 votes

Any tools (that actually work) for viewing PDF files in FreeDOS?

I discovered the answer on my own. Turns out PSVIEW requires GhostScript, PDFTOPS, and LXPIC to be installed on the hard drive in order to run. GhostScript must be placed in 'C:\gs'. PDFTOPS and ...
old_school9999's user avatar
19 votes

Why didn't C++ specify filename extensions?

I wonder why Dr. Stroustrup chose not to be specific about this issue himself? You'll have to ask him. But based on what I've read from his website, he seems not to be strongly opinionated on ...
dan04's user avatar
  • 964
19 votes

Document format for a DOS word processor where control commands begin with a dot

Looks to me like a set of dot commands found at the beginning of a Wordstar file .mt1 margin at top, .hm heading margin. Try Wordstar 3 Unfortunately, modern word processors that I know of don't have ...
camelccc's user avatar
  • 645
19 votes
Accepted

Document format for a DOS word processor where control commands begin with a dot

WordTsar – A Wordstar clone might be able to read the files. It is open-source and cross-platform. Compatibility depends on the version of WordStar used to write the files. It does implement an ...
scruss's user avatar
  • 21.6k
18 votes
Accepted

Why does the .z80 emulator-snapshot format have separate fields for the 8-bit refresh register and bit 7 of R?

The .z80 format comes from the Z80 emulator by Gerton Lunter. He released some documentation about the file formats used in it, and regarding offsets 11 and 12, this is what the manual says: .Z80 ...
mcleod_ideafix's user avatar
18 votes

Why does the default base64 encoding use forward slash /?

This answer is speculation but it's too long for a comment and I suspect any answer is likely to involve some speculation. We can however look to RFC821, the famous Simple Mail Transfer Protocol (...
JeremyP's user avatar
  • 11.8k
17 votes
Accepted

How are File Timestamps recorded in classic Mac OS?

The HFS filesystem stores file metadata in a single large file called the "catalog file", with one record for each file or directory. Creation and modification times are stored as 32-bit unsigned ...
Mark's user avatar
  • 8,576
17 votes
Accepted

How to convert Amiga DMS to ADF?

From some quick research, WinUAE (a popular Amiga emulator) supports reading a DMS file just like an ADF. So you could probably mount it and then save it back as ADF. Also, according to the ADF Opus ...
Thraka's user avatar
  • 2,913
17 votes

Do the holes in Jacquard loom punched cards represent input data or program code?

Program code for modern CPUs, in practice, consists of opcodes which tell the CPU what operation to perform, and operands which provide data to operate on. In RISC CPUs these are necessarily both ...
Chromatix's user avatar
  • 16.8k

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